Real-time PCR analysis of Vibrio vulnificus from oysters.
AuthorsCampbell MS, Wright AC
JournalAppl Environ Microbiol
PubMed ID14660359
Vibrio vulnificus is an opportunistic human pathogen commonly found in estuarine environments. Infections are associated with raw oyster consumption and can produce rapidly fatal septicemia in susceptible individuals. Standard enumeration of this organism in shellfish or seawater is laborious and inaccurate; therefore, more efficient assays are needed. An oligonucleotide probe ... More
Ethidium monoazide for DNA-based differentiation of viable and dead bacteria by 5'-nuclease PCR.
AuthorsNogva HK, Drømtorp SM, Nissen H, Rudi K
JournalBiotechniques
PubMed ID12703305
'PCR techniques have significantly improved the detection and identification of bacterial pathogens. Even so, the lack of differentiation between DNA from viable and dead cells is one of the major challenges for diagnostic DNA-based methods. Certain nucleic acid-binding dyes can selectively enter dead bacteria and subsequently be covalently linked to ... More
Escherichia coli cells with increased levels of DnaA and deficient in recombinational repair have decreased viability.
'The dnaA operon of Escherichia coli contains the genes dnaA, dnaN, and recF encoding DnaA, beta clamp of DNA polymerase III holoenzyme, and RecF. When the DnaA concentration is raised, an increase in the number of DNA replication initiation events but a reduction in replication fork velocity occurs. Because DnaA ... More
Substratum topography influences susceptibility of Salmonella enteritidis biofilms to trisodium phosphate.
AuthorsKorber DR, Choi A, Wolfaardt GM, Ingham SC, Caldwell DE
JournalAppl Environ Microbiol
PubMed ID9292984
'Established (48- and 72-h) Salmonella enteritidis biofilms grown in glass flow cells with or without artificial crevices (0.5-, 0.3-, and 0.15-mm widths) were subjected to a 10% trisodium phosphate (TSP) solution under different flow regimens (0.3, 0.6, 1.2, and 1.8 cm s-1). The abundance of biofilm remaining after TSP treatment, ... More
Phagosomal maturation and intracellular survival of Mycobacterium avium subspecies paratuberculosis in J774 cells.
AuthorsHostetter J, Steadham E, Haynes J, Bailey T, Cheville N
JournalComp Immunol Microbiol Infect Dis
PubMed ID12676127
'The mechanisms by which Mycobacterium avium subspecies paratuberculosis (M. a. ptb) survives within macrophages are not well characterized. One strategy for intracellular survival developed by Mycobacterium tuberculosis is inhibition of phagosomal maturation. In this study it was hypothesized that M. a. ptb is capable of survival within macrophages by residing ... More
Combination of immunosensor detection with viability testing and confirmation using the polymerase chain reaction and culture.
AuthorsJohnson-White B, Lin B, Ligler FS
JournalAnal Chem
PubMed ID17194131
'Rapid and accurate differential determination of viable versus nonviable microbes is critical for formulation of an appropriate response after pathogen detection. Sensors for rapid bacterial identification can be used for applications ranging from environmental monitoring and homeland defense to food process monitoring, but few provide viability information. This study combines ... More
Analysis of molecular diffusion in ftsK cell-division mutants using laser surgery.
AuthorsGoksör M, Diez A, Enger J, Hanstorp D, Nyström T
JournalEMBO Rep
PubMed ID12947413
'Escherichia coli cells that lack the carboxy-terminal part of FtsK fail to segregate their chromosomes properly during cytokinesis and tend to form chains. These chains are possibly formed as a result of DNA being trapped in the division planes or a failure to fuse the membrane during septum formation. If ... More
Use of confocal microscopy to analyze the rate of vancomycin penetration through Staphylococcus aureus biofilms.
AuthorsJefferson KK, Goldmann DA, Pier GB
JournalAntimicrob Agents Chemother
PubMed ID15917548
'When bacteria assume the biofilm mode of growth, they can tolerate levels of antimicrobial agents 10 to 1,000 times higher than the MICs of genetically equivalent planktonic bacteria. The properties of biofilms that give rise to antibiotic resistance are only partially understood. Inhibition of antibiotic penetration into the biofilm may ... More
Mechanism of microbial aggregation during capillary electrophoresis.
AuthorsZheng J, Yeung ES
JournalAnal Chem
PubMed ID12622372
'We studied the aggregation of a rod-shaped bacteria, Bifidobacterium infantis, during capillary electrophoresis (CE). A microscope with an intensified CCD camera was employed to monitor the migration and aggregation of bacteria, which are labeled with fluorescent dye Syto 9 and excited with a 488-nm argon ion laser. A collision-based aggregation ... More
Survival of FimH-expressing enterobacteria in macrophages relies on glycolipid traffic.
AuthorsBaorto DM, Gao Z, Malaviya R, Dustin ML, van der Merwe A, Lublin DM, Abraham SN
JournalNature
PubMed ID9335508
'Strains of Escherichia coli persist within the human gut as normal commensals, but are frequent pathogens and can cause recurrent infection. Here we show that, in contrast to E. coli subjected to opsonic interactions stimulated by the host''s immune response, E. coli that bind to the macrophage surface exclusively through ... More
Mechanisms of killing of Bacillus subtilis spores by hypochlorite and chlorine dioxide.
AuthorsYoung SB, Setlow P
JournalJ Appl Microbiol
PubMed ID12807454
'AIMS: To determine the mechanisms of Bacillus subtilis spore killing by hypochlorite and chlorine dioxide, and its resistance against them. METHODS AND RESULTS: Spores of B. subtilis treated with hypochlorite or chlorine dioxide did not accumulate damage to their DNA, as spores with or without the two major DNA protective ... More
Detection of bacterial contamination in starch and resin-based papermaking chemicals using fluorescence techniques.
AuthorsNohynek L, Saski E, Haikara A, Raaska L
JournalJ Ind Microbiol Biotechnol
PubMed ID12720090
'Rapid fluorescence techniques were evaluated for the detection of bacterial contaminants in papermaking chemicals including starch and the resin-based sizes and starch slurries used in the paper industry. Viable and non-viable bacterial cells were visualised by fluorescent probes and detected by epifluorescence microscopy and flow cytometry. The best discrimination ability ... More
Direct in situ viability assessment of bacteria in probiotic dairy products using viability staining in conjunction with confocal scanning laser microscopy.
AuthorsAuty MA, Gardiner GE, McBrearty SJ, O'Sullivan EO, Mulvihill DM, Collins JK, Fitzgerald GF, Stanton C, Ross RP
JournalAppl Environ Microbiol
PubMed ID11133474
'The viability of the human probiotic strains Lactobacillus paracasei NFBC 338 and Bifidobacterium sp. strain UCC 35612 in reconstituted skim milk was assessed by confocal scanning laser microscopy using the LIVE/DEAD BacLight viability stain. The technique was rapid (<30 min) and clearly differentiated live from heat-killed bacteria. The microscopic enumeration ... More
Starvation of Flavobacterium psychrophilum in broth, stream water and distilled water.
AuthorsVatsos IN, Thompson KD, Adams A
JournalDis Aquat Organ
PubMed ID14598987
'Physical changes in Flavobacterium psychrophilum, the causative agent of rainbow trout fry syndrome (RTFS), were examined over a 19 wk period of starvation. Bacteria were maintained in either Cytophaga broth, filtered stream water, or filtered distilled water, or were maintained in broth after disinfection as a negative control for dead ... More
Novel alpha-pyrones produced by a marine Pseudomonas sp. F92S91: taxonomy and biological activities.
AuthorsSingh MP, Kong F, Janso JE, Arias DA, Suarez PA, Bernan VS, Petersen PJ, Weiss WJ, Carter G, Greenstein M
JournalJ Antibiot (Tokyo)
PubMed ID15015731
'Inhibitors of the enzymes involved in fatty acid biosynthesis (FAB) have been reported as antibacterial agents. These include thiolactomycin, cerulenin, triclosan, diazoborine, naphthyridinones, aminopyridines and pyridoindoles. Our search for new FAB inhibitors, using a lacZ reporter cell-based screen, led to several confirmed hits. Culture F92S91, later identified as a Pseudomonas ... More
Nuclease activities and cell death processes associated with the development of surface cultures of Streptomyces antibioticus ETH 7451.
AuthorsFernández M, Sánchez J
JournalMicrobiology
PubMed ID11832504
'The presence and significance of developmentally regulated nucleases in Streptomyces antibioticus ETH 7451 has been studied in relation to the lytic processes occurring during differentiation. The cell-death processes have been followed in surface cultures by a propidium iodide viability assay. This has allowed the visualization of dead (membrane-damaged, red fluorescent) ... More
Significance of size and nucleic acid content heterogeneity as measured by flow cytometry in natural planktonic bacteria.
AuthorsGasol JM, Zweifel UL, Peters F, Fuhrman JA, Hagström A
JournalAppl Environ Microbiol
PubMed ID10508078
'Total bacterial abundances estimated with different epifluorescence microscopy methods (4'',6-diamidino-2-phenylindole [DAPI], SYBR Green, and Live/Dead) and with flow cytometry (Syto13) showed good correspondence throughout two microcosm experiments with coastal Mediterranean water. In the Syto13-stained samples we could differentiate bacteria with apparent high DNA (HDNA) content and bacteria with apparent low ... More
Molecular, biochemical and ecological characterisation of a bio-catalytic calcification reactor.
AuthorsHammes F, Boon N, Clement G, de Villiers J, Siciliano SD, Verstraete W
JournalAppl Microbiol Biotechnol
PubMed ID12883864
'Bio-catalytic calcification (BCC) reactors utilise microbial urea hydrolysis by autochthonous bacteria for the precipitation-removal of calcium, as calcite, from industrial wastewater. Due to the limited knowledge available concerning natural ureolytic microbial calcium carbonate (CaCO(3)) precipitation, the microbial ecology of BCC reactors has remained a black box to date. This paper ... More
The MspA porin promotes growth and increases antibiotic susceptibility of both Mycobacterium bovis BCG and Mycobacterium tuberculosis.
AuthorsMailaender C, Reiling N, Engelhardt H, Bossmann S, Ehlers S, Niederweis M
JournalMicrobiology
PubMed ID15073295
'Porins mediate the diffusion of hydrophilic solutes across the outer membrane of mycobacteria, but the efficiency of this pathway is very low compared to Gram-negative bacteria. To examine the importance of porins in slow-growing mycobacteria, the major porin MspA of Mycobacterium smegmatis was expressed in Mycobacterium tuberculosis and Mycobacterium bovis. ... More
High-content screening for biofilm assays.
AuthorsPeng F, Hoek EM, Damoiseaux R,
JournalJ Biomol Screen
PubMed ID20639506
'The authors describe a novel high-throughput screening platform that provides rapid, reliable, quantitative assessment of biofilm formation and removal on engineered surfaces. Unlike traditional biofilm assays based on plate readers, this assay platform is based on high-content screening, which allows for multiplexing to simultaneously quantify the number of bacterial adhesions ... More
Mechanistic aspects in the generation of apparent ultrahigh efficiencies for colloidal (microbial) electrokinetic separations.
AuthorsArmstrong DW, Girod M, He L, Rodriguez MA, Wei W, Zheng J, Yeung ES
JournalAnal Chem
PubMed ID12433083
'Under specific experimental conditions, the electrokinetic separation of certain microorganisms can produce peaks of very high apparent efficiencies (approximately 10(6)-10(10) theoretical plates/m). This is unusual in that no deliberate focusing mechanism was employed. To investigate this process further, the separation was monitored in real time using a charge-coupled device (CCD) ... More
Induction of TNF in human alveolar macrophages as a potential evasion mechanism of virulent Mycobacterium tuberculosis.
AuthorsEngele M, Stössel E, Castiglione K, Schwerdtner N, Wagner M, Bölcskei P, Röllinghoff M, Stenger S
JournalJ Immunol
PubMed ID11801673
'The ability of macrophages to release cytokines is crucial to the host response to intracellular infection. In particular, macrophage-derived TNF plays an important role in the host response to infection with the intracellular pathogen Mycobacterium tuberculosis. In mice, TNF is indispensable for the formation of tuberculous granulomas, which serve to ... More
Predicting the effects of chlorine on the micro-organisms of filamentous bulking activated sludges.
AuthorsSéka MA, Hammes F, Verstraete W
JournalAppl Microbiol Biotechnol
PubMed ID12764574
'Rapid and definite assessment of the effect that a specific biocide has on a specific case of filamentous bulking sludge is a much-needed tool in activated sludge wastewater treatment. The Live/Dead stain (LIVE/DEAD BacLight) distinguishing "living" and "non-living" cells, a nitrifying activity (NA) test and the oxygen uptake rate (OUR) ... More
Synthesis and characterization of non-leaching biocidal polyurethanes.
AuthorsGrapski JA, Cooper SL
JournalBiomaterials
PubMed ID11456063
'The biocidal activities of a series of quaternized polyurethanes were examined against Staphylococcus aureus and Escherichia coli. The percentage of dead cells on a surface was found to depend on the alkyl halide used for quaternization, the concentration of quaternized moieties in the polyurethane, the gram-type of the microorganism, and ... More
Surfaces of fluorinated pyridinium block copolymers with enhanced antibacterial activity.
AuthorsKrishnan S, Ward RJ, Hexemer A, Sohn KE, Lee KL, Angert ER, Fischer DA, Kramer EJ, Ober CK
JournalLangmuir
PubMed ID17154613
'Polystyrene-b-poly(4-vinylpyridine) copolymers were quaternized with 1-bromohexane and 6-perfluorooctyl-1-bromohexane. Surfaces prepared from these polymers were characterized by contact angle measurements, near-edge X-ray absorption fine structure spectroscopy and X-ray photoelectron spectroscopy. The fluorinated pyridinium surfaces showed enhanced antibacterial activity compared to their nonfluorinated counterparts. Even a polymer with a relatively low molecular ... More
Localizing and identifying living bacteria in an abiotic environment by a combination of Raman and fluorescence microscopy.
AuthorsKrause M, Rösch P, Radt B, Popp J,
JournalAnal Chem
PubMed ID18847286
'A fast, easy, and reliable identification of microorganisms is indispensable in many fields such as medicine, food production, or the pharmaceutical industry. However, in native samples, biotic particles often appear together with abiotic particles. Therefore, it is a prerequisite that biotic particles can be differentiated from abiotic particles appearing in ... More
A role for triggering receptor expressed on myeloid cells-1 in host defense during the early-induced and adaptive phases of the immune response.
'Triggering receptor expressed on myeloid cells (TREM)-1 is a cell surface molecule expressed on neutrophils and monocytes implicated in the propagation of the inflammatory response. To further characterize the function of this molecule in different phases of the immune response, we examined TREM-1 in the context of host defense against ... More
Rapid, absolute, and simultaneous quantification of specific pathogenic strain and total bacterial cells using an ultrasensitive dual-color flow cytometer.
AuthorsYang L, Wu L, Zhu S, Long Y, Hang W, Yan X,
JournalAnal Chem
PubMed ID20039721
'This paper describes a rapid and sensitive strategy for the absolute and simultaneous quantification of specific pathogenic strain and total bacterial cells in a mixture. A laboratory-built compact, high-sensitivity, dual channel flow cytometer (HSDCFCM) was modified to enable dual fluorescence detection. A bacterial cell mixture comprising heat-killed pathogenic Escherichia coli ... More
Flow cytometric assessment of susceptibilities of Streptococcus pyogenes to erythromycin and rokitamycin.
AuthorsBraga PC, Bovio C, Culici M, Dal Sasso M
JournalAntimicrob Agents Chemother
PubMed ID12499226
'The effects of erythromycin (a 14-membered ring macrolide) and rokitamycin (a 16-membered ring macrolide) on the viability of the Streptococcus pyogenes M phenotype were studied by means of flow cytometry and fluorescence microscopy by using a combination of two fluorochromes (syto 9 and propidium iodide) that stains live bacteria green ... More
In vitro and in vivo antimicrobial activity of covalently coupled quaternary ammonium silane coatings on silicone rubber.
AuthorsGottenbos B, van der Mei HC, Klatter F, Nieuwenhuis P, Busscher HJ
JournalBiomaterials
PubMed ID11829437
'Biomaterial-centered infection is a dreaded complication associated with the use of biomedical implants. In this paper, the antimicrobial activity of silicone rubber with a covalently coupled 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride (QAS) coating was studied in vitro and in vivo. Gram-positive Staphylococcus aureus ATCC 12600, Staphylococcus epidermidis HBH, 102, and Gram-negative Esherichia coli ... More
LIVE/DEAD BacLight : application of a new rapid staining method for direct enumeration of viable and total bacteria in drinking water.
AuthorsBoulos L, Prévost M, Barbeau B, Coallier J, Desjardins R
JournalJ Microbiol Methods
PubMed ID10395466
'A rapid epifluorescence staining method using the LIVE/DEAD Bacterial Viability Kit (BacLight) was applied to estimate both viable and total counts of bacteria in drinking water. BacLight is composed of two nucleic acid-binding stains: SYTO 9 and propidium iodide. SYTO 9 penetrates all bacterial membranes and stains the cells green, ... More
Influence of storage on monodispersed cells of Mycobacterium terrae used for quantitative carrier test prEN 14563.
AuthorsWoelk E, Goroncy-Bermes P, Sand W
JournalAppl Environ Microbiol
PubMed ID14602657
'The degree of cell clumping increased with time of storage (1% cell clumps immediately after homogenization and 3 and 6.5% after 48 and 96 h of storage, respectively), and the number of living single cells decreased. Quantitative carrier tests were carried out with these cells using ortho-phthaldialdehyde (OPA) and coco ... More
Persistence and cell culturability of biocontrol strain Pseudomonas fluorescens CHA0 under plough pan conditions in soil and influence of the anaerobic regulator gene anr.
AuthorsMascher F, Schnider-Keel U, Haas D, Défago G, Moënne-Loccoz Y
JournalEnviron Microbiol
PubMed ID12558593
'Certain fluorescent pseudomonads can protect plants from soil-borne pathogens, and it is important to understand how these biocontrol agents survive in soil. The persistence of the biocontrol strain Pseudomonas fluorescens CHA0-Rif under plough pan conditions was assessed in non-sterile soil microcosms by counting total cells (immunofluorescence microscopy), intact cells (BacLight ... More
Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae.
'Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces. Alternatively, it has been proposed that bacterial pathogens are an ... More
Growth characteristics of Bartonella henselae in a novel liquid medium: primary isolation, growth-phase-dependent phage induction, and metabolic studies.
AuthorsChenoweth MR, Somerville GA, Krause DC, O'Reilly KL, Gherardini FC
JournalAppl Environ Microbiol
PubMed ID14766538
'Bartonella henselae is a zoonotic pathogen that usually causes a self-limiting infection in immunocompetent individuals but often causes potentially life-threatening infections, such as bacillary angiomatosis, in immunocompromised patients. Both diagnosis of infection and research into the molecular mechanisms of pathogenesis have been hindered by the absence of a suitable liquid ... More
Survival of Helicobacter pylori in a natural freshwater environment.
AuthorsAdams BL, Bates TC, Oliver JD
JournalAppl Environ Microbiol
PubMed ID14660399
'The mode by which Helicobacter pylori, the causative agent of most gastric ulcers, is transmitted remains undetermined. Epidemiological evidence suggests these organisms are waterborne; however, H. pylori has rarely been grown from potential water sources. This may be due to the ability of this organism to rapidly enter the viable ... More
par genes and the pathology of chromosome loss in Vibrio cholerae.
AuthorsYamaichi Y, Fogel MA, Waldor MK
JournalProc Natl Acad Sci U S A
PubMed ID17197419
'The causes and consequences of chromosome loss in bacteria with multiple chromosomes are unknown. Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, has two circular chromosomes. Like many other bacterial chromosomes, both V. cholerae chromosomes contain homologues of plasmid partitioning (par) genes. In plasmids, par genes act ... More
Cell lysis and protein extraction in a microfluidic device with detection by a fluorogenic enzyme assay.
AuthorsSchilling EA, Kamholz AE, Yager P
JournalAnal Chem
PubMed ID11985310
'A critical requirement for achieving a micro total analytical system for the analysis of cells and their constituent proteins is to integrate the lysis and fractionation steps on-chip. Here, an experimental microfluidic system integrating the lysis of bacterial cells and the extraction of a large intracellular enzyme, beta-galactosidase, is demonstrated. ... More
Differential trafficking of live and dead Mycobacterium marinum organisms in macrophages.
AuthorsBarker LP, George KM, Falkow S, Small PL
JournalInfect Immun
PubMed ID9119492
'We characterized the Mycobacterium marinum phagosome by using a variety of endocytic markers to follow the path of the bacteria through a mouse macrophage cell line. Using a laser confocal microscope, we found that the majority of viable M. marinum cells were in nonacidic vacuoles that did not colocalize with ... More
Phylogenetic and physiological diversity of microorganisms isolated from a deep greenland glacier ice core.
AuthorsMiteva VI, Sheridan PP, Brenchley JE
JournalAppl Environ Microbiol
PubMed ID14711643
'We studied a sample from the GISP 2 (Greenland Ice Sheet Project) ice core to determine the diversity and survival of microorganisms trapped in the ice at least 120,000 years ago. Previously, we examined the phylogenetic relationships among 16S ribosomal DNA (rDNA) sequences in a clone library obtained by PCR ... More
Laser-induced fluorescence-capillary electrophoresis and fluorescence microplate reader measurement: two methods to quantify the effect of antibiotics.
AuthorsHoerr V, Ziebuhr W, Kozitskaya S, Katzowitsch E, Holzgrabe U,
JournalAnal Chem
PubMed ID17784732
'Putative antibiotic drugs have to be classified according to their bactericidal potential. Two new methods by means of fluorescence spectroscopy (FS) using a fluorescence microplate reader (FMR) and laser-induced fluorescence capillary electrophoresis (LIF-CE), respectively, were developed for the assessment of the bactericidal efficiency using the LIVE/DEAD BacLight viability kit composed ... More
Okadaic acid-induced apoptosis in neuronal cells: evidence for an abortive mitotic attempt.
AuthorsNuydens R, de Jong M, Van Den Kieboom G, Heers C, Dispersyn G, Cornelissen F, Nuyens R, Borgers M, Geerts H
JournalJ Neurochem
PubMed ID9489733
'There is increasing evidence that apoptosis in postmitotic neurons is associated with a frustrated attempt to reenter the mitotic cycle. Okadaic acid, a specific protein phosphatase inhibitor, is currently used in models of Alzheimer''s research to increase the degree of phosphorylation of various proteins, such as the microtubule-associated protein tau. ... More
Influence of trehalose 6,6'-dimycolate (TDM) during mycobacterial infection of bone marrow macrophages.
AuthorsIndrigo J, Hunter RL, Actor JK
JournalMicrobiology
PubMed ID12101287
'The relative role of surface lipids in the innate macrophage response to infection with mycobacteria remains unknown. Trehalose 6,6''-dimycolate (TDM), a major component of the mycobacterial cell wall, can elicit hypersensitive as well as T-cell-independent foreign body responses. The T-cell-independent contribution of TDM to the primary macrophage response to mycobacterial ... More
Phylogenetic analysis of anaerobic psychrophilic enrichment cultures obtained from a greenland glacier ice core.
AuthorsSheridan PP, Miteva VI, Brenchley JE
JournalAppl Environ Microbiol
PubMed ID12676695
'The examination of microorganisms in glacial ice cores allows the phylogenetic relationships of organisms frozen for thousands of years to be compared with those of current isolates. We developed a method for aseptically sampling a sediment-containing portion of a Greenland ice core that had remained at -9 degrees C for ... More
Comparison of SYTO9 and SYBR Green I for real-time polymerase chain reaction and investigation of the effect of dye concentration on amplification and DNA melting curve analysis.
AuthorsMonis PT, Giglio S, Saint CP
JournalAnal Biochem
PubMed ID15802126
'Following the initial report of the use of SYBR Green I for real-time polymerase chain reaction (PCR) in 1997, little attention has been given to the development of alternative intercalating dyes for this application. This is surprising considering the reported limitations of SYBR Green I, which include limited dye stability, ... More
Fluorescent method for monitoring cheese starter permeabilization and lysis.
'A fluorescence method to monitor lysis of cheese starter bacteria using dual staining with the LIVE/DEAD BacLight bacterial viability kit is described. This kit combines membrane-permeant green fluorescent nucleic acid dye SYTO 9 and membrane-impermeant red fluorescent nucleic acid dye propidium iodide (PI), staining damaged membrane cells fluorescent red and ... More
Epifluorescence microscope methods for bacterial enumeration in a 4-chlorophenol degrading consortium.
AuthorsPacheco CC, Alves CC, Barreiros L, Castro PM, Teixeira PC
JournalBiotechnol Lett
PubMed ID14969414
'Epifluorescence microscope methods, namely BacLight, direct epifluorescence filter technique and Rhodamine 123, consistently underestimated plate bacterial counts in a 4-chlorophenol degrading consortium. Cells capable of passing through 0.2 microm filters, referred as ''ultramicrocells'', were found. Although cell counts were higher when traditional methods were used, BacLight and direct epifluorescence filter ... More
Comparison of multiple methods for quantification of microbial biofilms grown in microtiter plates.
AuthorsPeeters E, Nelis HJ, Coenye T,
JournalJ Microbiol Methods
PubMed ID18155789
'In the present study six assays for the quantification of biofilms formed in 96-well microtiter plates were optimised and evaluated: the crystal violet (CV) assay, the Syto9 assay, the fluorescein diacetate (FDA) assay, the resazurin assay, the XTT assay and the dimethyl methylene blue (DMMB) assay. Pseudomonas aeruginosa, Burkholderia cenocepacia, ... More
Biofilm formation by hyperpiliated mutants of Pseudomonas aeruginosa.
AuthorsChiang P, Burrows LL
JournalJ Bacteriol
PubMed ID12644510
Under static growth conditions, hyperpiliated, nontwitching pilT and pilU mutants of Pseudomonas aeruginosa formed dense biofilms, showing that adhesion, not twitching motility, is necessary for biofilm initiation. Under flow conditions, the pilT mutant formed mushroom-like structures larger than those of the wild type but the pilU mutant was defective in ... More
High-resolution DNA melt curve analysis of the clustered, regularly interspaced short-palindromic-repeat locus of Campylobacter jejuni.
AuthorsPrice EP, Smith H, Huygens F, Giffard PM,
JournalAppl Environ Microbiol
PubMed ID17400785
A novel method for genotyping the clustered, regularly interspaced short-palindromic-repeat (CRISPR) locus of Campylobacter jejuni is described. Following real-time PCR, CRISPR products were subjected to high-resolution melt (HRM) analysis, a new technology that allows precise melt profile determination of amplicons. This investigation shows that the CRISPR HRM assay provides a ... More
Expression of Vibrio vulnificus capsular polysaccharide inhibits biofilm formation.
AuthorsJoseph LA, Wright AC
JournalJ Bacteriol
PubMed ID14729720
Vibrio vulnificus is a human pathogen that produces lethal septicemia in susceptible persons, and the primary virulence factor for this organism is capsular polysaccharide (CPS). The role of the capsule in V. vulnificus biofilms was examined under a variety of conditions, by using either defined CPS mutants or spontaneous CPS ... More
Monitoring biofilm formation and activity in drinking water distribution networks under oligotrophic conditions.
AuthorsBoe-Hansen R, Martiny AC, Arvin E, Albrechtsen HJ
JournalWater Sci Technol
PubMed ID12701912
In this study, the construction a model distribution system suitable for studies of attached and suspended microbial consisted of two loops connected in series with a total of 140 biofilm sampling points. The biofilm from the system was studied using 11 different microbial methods and the results were compared and ... More
Comparison of animal infectivity and nucleic acid staining for assessment of Cryptosporidium parvum viability in water.
AuthorsNeumann NF, Gyürek LL, Gammie L, Finch GR, Belosevic M
JournalAppl Environ Microbiol
PubMed ID10618255
Cryptosporidium parvum oocysts were stained with the fluorogenic dyes SYTO-9 and SYTO-59 and sorted by flow cytometry in order to determine whether the fluorescent staining intensity correlated with the ability of oocysts to infect neonatal CD-1 mice. Oocysts that did not fluoresce or that displayed weak fluorescent intensity when stained ... More
Optimization of a rapid and sensitive identification system for Salmonella enteritidis by capillary electrophoresis with laser-induced fluorescence.
AuthorsShintani T, Yamada K, Torimura M
JournalFEMS Microbiol Lett
PubMed ID12044682
A system coupling capillary electrophoresis (CE) with a laser-induced fluorescence (LIF) system for the identification of Salmonella enteritidis was developed. Addition of an appropriate amount of sodium alginate and NaCl to the running buffer made it possible to obtain a reproducible sharp peak. Two fluorescent staining methods using a cell-permeable ... More
Determination of cell viability in single or mixed samples using capillary electrophoresis laser-induced fluorescence microfluidic systems.
AuthorsArmstrong DW, He L
JournalAnal Chem
PubMed ID11605830
The advent of high-efficiency microbial separations will have a profound effect on both chemistry and microbiology. For the first time, it appears that it may be possible to obtain qualitative and quantitative information on microbial systems with the accuracy, precision, speed, and throughput that currently is found for chemical systems. ... More
Physiological changes of Salmonella typhimurium cells under osmotic and starvation conditions by image analysis.
AuthorsCaro A, Got P, Baleux B
JournalFEMS Microbiol Lett
PubMed ID10518725
The effects of starvation and salinity on the physiology of Salmonella typhimurium were investigated in a microcosm study. The physiological changes were monitored by using fluorochromes dyes such as DAPI (4',6-diamidino-2-phenylindole) for evaluation of the genomic content, CTC (5-cyano-2,3-ditolyl tetrazolium chloride) for respiratory activity and syto 9 and propidium iodide ... More
Hyaluronan release from Streptococcus pyogenes: export by an ABC transporter.
AuthorsOuskova G, Spellerberg B, Prehm P
JournalGlycobiology
PubMed ID15215229
Capsular hyaluronan of Streptococcus pyogenes is synthesized at the protoplast membrane. It is widely assumed that hyaluronan is exported by the synthase itself and that no additional protein is required for transfer through plasma membranes. However, we produced an insertional mutation that reduced the mucoid phenotype, hyaluronan production, and capsule ... More
Establishment of a pure culture of the hitherto uncultured unicellular cyanobacterium Aphanothece sacrum, and phylogenetic position of the organism.
AuthorsFujishiro T, Ogawa T, Matsuoka M, Nagahama K, Takeshima Y, Hagiwara H
JournalAppl Environ Microbiol
PubMed ID15184129
Aphanothece sacrum, an edible freshwater unicellular cyanobacterium, was isolated by using novel synthetic media (designated AST and AST-5xNP). The media were designed on the basis of the ratio of inorganic elements contained in A. sacrum cells cultured in a natural pond. The isolated strain exhibits unicellular rod-shaped cells approximately 6 ... More
Quantitative evaluation of DNA methylation by optimization of a differential-high resolution melt analysis protocol.
DNA methylation is a key regulator of gene transcription. Alterations in DNA methylation patterns are common in most cancers, occur early in carcinogenesis and can be detected in body fluids. Reliable and sensitive quantitative assays are required to improve the diagnostic role of methylation in the management of cancer patients. ... More
Sequential treatment of drug-resistant tumors with targeted minicells containing siRNA or a cytotoxic drug.
The dose-limiting toxicity of chemotherapeutics, heterogeneity and drug resistance of cancer cells, and difficulties of targeted delivery to tumors all pose daunting challenges to effective cancer therapy. We report that small interfering RNA (siRNA) duplexes readily penetrate intact bacterially derived minicells previously shown to cause tumor stabilization and regression when ... More
Mechanism and use of the commercially available viability stain, BacLight.
AuthorsStocks SM,
JournalCytometry A
PubMed ID15382024
BACKGROUND: BacLight (Molecular Probes, Eugene, OR, USA) is a popular fluorescence-based two-component stain for determining bacterial cell viability. The main purpose of this work was to fully elucidate the mechanism and to determine why it is sometimes reported that cells stain simultaneously live and dead. METHODS: Solutions of DNA were ... More
Viability of endolithic micro-organisms in rocks from the McMurdo Dry Valleys of Antarctica established by confocal and fluorescence microscopy.
AuthorsWierzchos J, De Los Ríos A, Sancho LG, Ascaso C,
JournalJ Microsc
PubMed ID15369484
The rocks of the McMurdo Dry Valleys desert in Antarctica harbour endolithic communities of micro-organisms such as lichens, fungi, cyanobacteria and bacteria. Establishing the physiological status and viability of these microbial colonies in their natural microhabitat has far-reaching implications for understanding the microbial ecology of the harsh environment of this ... More
The response of Cupriavidus metallidurans CH34 to spaceflight in the international space station.
AuthorsLeys N, Baatout S, Rosier C, Dams A, s'Heeren C, Wattiez R, Mergeay M,
JournalAntonie Van Leeuwenhoek
PubMed ID19572210
The survival and behavior of Cupriavidus metallidurans strain CH34 were tested in space. In three spaceflight experiments, during three separate visits to the 'International Space Station' (ISS), strain CH34 was grown for 10-12 days at ambient temperature on mineral agar medium. Space- and earth-grown cells were compared post-flight by flow ... More
Increased sensitivity of bacterial detection in cerebrospinal fluid by fluorescent staining on low-fluorescence membrane filters.
AuthorsDurtschi JD, Erali M, Bromley LK, Herrmann MG, Petti CA, Smith RE, Voelkerding KV
JournalJ Med Microbiol
PubMed ID16091435
A membrane-filter-based, fluorescent Gram stain method for bacterial detection in cerebrospinal fluid samples was developed and evaluated as a rapid, sensitive alternative to standard Gram stain protocols. A recently developed, modified version of the aluminium oxide membrane Anopore with low-fluorescence optical properties showed superior performance in this application. Other aspects ... More
Selective chemical treatment of cellular microdomains using multiple laminar streams.
AuthorsTakayama S, Ostuni E, LeDuc P, Naruse K, Ingber DE, Whitesides GM
JournalChem Biol
PubMed ID12618184
There are many experiments in which it would be useful to treat a part of the surface or interior of a cell with a biochemical reagent. It is difficult, however, to achieve subcellular specificity, because small molecules diffuse distances equal to the extent of the cell in seconds. This paper ... More
Viability staining and terminal deoxyribonucleotide transferase-mediated dUTP nick end labelling of the mycelium in submerged cultures of Streptomyces antibioticus ETH7451.
AuthorsFernandez M, Sanchez J
JournalJ Microbiol Methods
PubMed ID11714519
Viability stain and terminal deoxyribonucleotide transferase-mediated dUTP nick end labelling (TUNEL) have been applied to submerged cultures of Streptomyces antibioticus ETH7451, the last technique after a suitable permeabilization treatment. Areas of dead mycelium can be clearly delineated by the viability stain within the network of hyphae which forms the mycelial ... More
Dendritic cells are host cells for mycobacteria in vivo that trigger innate and acquired immunity.
AuthorsJiao X, Lo-Man R, Guermonprez P, Fiette L, Dériaud E, Burgaud S, Gicquel B, Winter N, Leclerc C
JournalJ Immunol
PubMed ID11801668
In the present study, we investigated in vivo the infection and APC functions of dendritic cells (DC) and macrophages (Mphi) after administration of live mycobacteria to mice. Experiments were conducted with Mycobacterium bovis bacillus Calmette-Guerin (BCG) or a rBCG expressing a reporter Ag. Following infection of mice, DC and Mphi ... More
Nucleic acid stains as indicators of Cryptosporidium parvum oocyst viability.
AuthorsBelosevic M, Guy RA, Taghi-Kilani R, Neumann NF, Gyürék LL, Liyanage LR, Millard PJ, Finch GR
JournalInt J Parasitol
PubMed ID9279581
We developed nucleic acid dye staining methodology for untreated, heat-treated and chemically inactivated C. parvum oocysts. The nucleic acid staining was compared to in vitro excystation and animal infectivity using split samples of oocysts. Among the nucleic acid stains tested, SYTO-9, hexidium and SYTO-59 stained the oocysts consistently, and the ... More
Flow cytometry demonstrates bacteriocin-induced injury to Listeria monocytogenes.
AuthorsSwarts AJ, Hastings JW, Roberts RF, von Holy A
JournalCurr Microbiol
PubMed ID9541561
Flow cytometry was used to study the effect of the bacteriocin leucocin B-TA11a on Listeria (L.) monocytogenes. Mixed proportions of dead and live control populations were analyzed by flow cytometry to determine detection limits of the Dead/Live Baclight Bacterial Viability KitTM. High correlations for flow cytometric detection of defined proportions ... More
Differential oxidative damage and expression of stress defence regulons in culturable and non-culturable Escherichia coli cells.
Potentially pathogenic bacteria, such as Escherichia coli and Vibrio cholerae, become non-culturable during stasis. The analysis of such cells has been hampered by difficulties in studying bacterial population heterogeneity. Using in situ detection of protein oxidation in single E. coli cells, and using a density-gradient centrifugation technique to separate culturable ... More
Cutting edge: dendritic cells copulsed with microbial and helminth antigens undergo modified maturation, segregate the antigens to distinct intracellular compartments, and concurrently induce microbe-specific Th1 and helminth-specific Th2 responses.
AuthorsCervi L, MacDonald AS, Kane C, Dzierszinski F, Pearce EJ
JournalJ Immunol
PubMed ID14764665
To examine the ability of dendritic cells (DC) to discriminate between helminth and microbial Ag and induce appropriately polarized Th responses, mouse DC were copulsed with the helminth Ag, schistosome egg Ag (SEA), along with the bacterium Proprionebacterium acnes, Pa, and transferred into wild-type mice. Strikingly, SEA/Pa-copulsed DC induced concurrent ... More
The ability of direct fluorescence-based, two-colour assays to detect different physiological states of oral streptococci.
AuthorsDecker EM
JournalLett Appl Microbiol
PubMed ID11555201
AIMS: To investigate the ability of six fluorescent-based, two-colour viability assays to detect different physiological growth stages of two oral streptococci species. METHODS AND RESULTS: The growth of Streptococcus sanguinis and Strep. mutans from 0 to 73 h culture periods was monitored by cell labelling with six mixtures of fluorescent ... More
Validation of an in vitro biofilm model of supragingival plaque.
AuthorsGuggenheim B, Giertsen E, Schüpbach P, Shapiro S
JournalJ Dent Res
PubMed ID11269730
The study of biofilm structure and function mandates the use of model systems for which a host of environmental variables can be rigorously controlled. We describe a model of supragingival plaque containing Actinomyces naeslundii, Veillonella dispar, Fusobacterium nucleatum, Streptococcus sobrinus, and Streptococcus oralis wherein cells are cultivated anaerobically in a ... More
Method for collecting air-water interface microbes suitable for subsequent microscopy and molecular analysis in both research and teaching laboratories.
AuthorsHenk MC
JournalAppl Environ Microbiol
PubMed ID15066847
A method has been developed for collecting air-water interface (AWI) microbes and biofilms that enables analysis of the same sample with various combinations of bright-field and fluorescence light microscopy optics, scanning and transmission electron microscopy (TEM), and atomic force microscopy. The identical sample is then subjected to molecular analysis. The ... More
Two-pronged survival strategy for the major cystic fibrosis pathogen, Pseudomonas aeruginosa, lacking the capacity to degrade nitric oxide during anaerobic respiration.
Protection from NO gas, a toxic byproduct of anaerobic respiration in Pseudomonas aeruginosa, is mediated by nitric oxide (NO) reductase (NOR), the norCB gene product. Nevertheless, a norCB mutant that accumulated approximately 13.6 microM NO paradoxically survived anaerobic growth. Transcription of genes encoding nitrate and nitrite reductases, the enzymes responsible ... More
A microfluidic bioreactor based on hydrogel-entrapped E. coli: cell viability, lysis, and intracellular enzyme reactions.
AuthorsHeo J, Thomas KJ, Seong GH, Crooks RM
JournalAnal Chem
PubMed ID12530814
Viable E. coli cells were entrapped in hydrogel micropatches photopolymerized within microfluidic systems. The microfluidic channels and the micropatches have sizes on the order of 100-500 microm. Small molecules, such as dyes and surfactants, present in the solution surrounding the hydrogel, are able to diffuse into the gel and encounter ... More
Nucleic acid stains as indicators of Giardia muris viability following cyst inactivation.
AuthorsTaghi-Kilani R, Gyürék LL, Millard PJ, Finch GR, Belosevic M
JournalInt J Parasitol
PubMed ID8875309
A reliable viability assay for Giardia is required for the development of disinfection process design criteria and pathogen monitoring by water treatment utilities. Surveys of single-staining nucleic acid dyes (stain dead parasites only), and double-staining vital dye kits from Molecular Probes (stain live and dead parasites) were conducted to assess ... More
Cold and carbon dioxide used as multi-hurdle preservation do not induce appearance of viable but non-culturable Listeria monocytogenes.
AuthorsLi J, Kolling GL, Matthews KR, Chikindas ML
JournalJ Appl Microbiol
PubMed ID12492922
AIMS: To study whether the exposure to cold (4 degrees C) and carbon dioxide which results in the elongation of Listeria cells, induces a viable but nonculturable (VBNC) state. METHODS AND RESULTS: When cold and CO2 stressed L. monocytogenes were observed under a fluorescence microscope, using the LIVE/DEAD BacLight bacteria ... More
Determination of complement-mediated killing of bacteria by viability staining and bioluminescence.
AuthorsVirta M, Lineri S, Kankaanpää P, Karp M, Peltonen K, Nuutila J, Lilius EM
JournalAppl Environ Microbiol
PubMed ID9464386
Complement-mediated killing of bacteria was monitored by flow cytometric, luminometric, and conventional plate counting methods. A flow cytometric determination of bacterial viability was carried out by using dual staining with a LIVE/DEAD BacLight bacterial viability kit. In addition to the viable cell population, several other populations emerged in the fluorescence ... More
A genetic basis for Pseudomonas aeruginosa biofilm antibiotic resistance.
AuthorsMah TF, Pitts B, Pellock B, Walker GC, Stewart PS, O'Toole GA
JournalNature
PubMed ID14628055
Biofilms are surface-attached microbial communities with characteristic architecture and phenotypic and biochemical properties distinct from their free-swimming, planktonic counterparts. One of the best-known of these biofilm-specific properties is the development of antibiotic resistance that can be up to 1,000-fold greater than planktonic cells. We report a genetic determinant of this ... More
Toxicity of lead in aqueous medium to desulfovibrio desulfuricans G20.
AuthorsSani RK, Peyton BM, Jandhyala M
JournalEnviron Toxicol Chem
PubMed ID12558154
The toxicity of Pb(II) to sulfate-reducing bacteria (SRB) was studied using Desulfovibrio desulfuricans G20 in a medium specifically designed to assess metal toxicity. The effects of Pb(II) toxicity were observed in terms of longer lag times, lower specific growth rates, and in some cases no measurable growth. With an increase ... More
Microbial characterization of biofilms in domestic drains and the establishment of stable biofilm microcosms.
AuthorsMcBain AJ, Bartolo RG, Catrenich CE, Charbonneau D, Ledder RG, Rickard AH, Symmons SA, Gilbert P
JournalAppl Environ Microbiol
PubMed ID12513993
We have used heterotrophic plate counts, together with live-dead direct staining and denaturing gradient gel electrophoresis (DGGE), to characterize the eubacterial communities that had formed as biofilms within domestic sink drain outlets. Laboratory microcosms of these environments were established using excised biofilms from two separate drain biofilm samples to inoculate ... More
Assessment of bacterial endospore viability with fluorescent dyes.
AuthorsLaflamme C, Lavigne S, Ho J, Duchaine C
JournalJ Appl Microbiol
PubMed ID15012806
AIM: To validate three fluorescence viability assays designed primarily for vegetative cells on pure Bacillus endospores. METHODS AND RESULTS: Purified fresh and gamma-irradiated Bacillus endospores (Bacillus cereus, B. coagulans and two strains of B. subtilis) were used. The viability assays were: 5-cyano-2,3-diotolyl tetrazolium chloride (CTC) to test respiratory activity and ... More
Use of in-biofilm expression technology to identify genes involved in Pseudomonas aeruginosa biofilm development.
AuthorsFinelli A, Gallant CV, Jarvi K, Burrows LL
JournalJ Bacteriol
PubMed ID12700249
Mature Pseudomonas aeruginosa biofilms form complex three-dimensional architecture and are tolerant of antibiotics and other antimicrobial compounds. In this work, an in vivo expression technology system, originally designed to study virulence-associated genes in complex mammalian environments, was used to identify genes up-regulated in P. aeruginosa grown to a mature (5-day) ... More
Long-term anaerobic survival of the opportunistic pathogen Pseudomonas aeruginosa via pyruvate fermentation.
AuthorsEschbach M, Schreiber K, Trunk K, Buer J, Jahn D, Schobert M
JournalJ Bacteriol
PubMed ID15231792
Denitrification and arginine fermentation are central metabolic processes performed by the opportunistic pathogen Pseudomonas aeruginosa during biofilm formation and infection of lungs of patients with cystic fibrosis. Genome-wide searches for additional components of the anaerobic metabolism identified potential genes for pyruvate-metabolizing NADH-dependent lactate dehydrogenase (ldhA), phosphotransacetylase (pta), and acetate kinase ... More
Oriented adhesion of Escherichia coli to polystyrene particles.
AuthorsJones JF, Feick JD, Imoudu D, Chukwumah N, Vigeant M, Velegol D
JournalAppl Environ Microbiol
PubMed ID14602608
The adhesion of nonflagellated Escherichia coli strain K-12 to polystyrene (PS) latex spheres or glass capillaries has been observed by using several techniques. Attention was focused on the orientation of the rod-shaped bacteria as they adhered to the surfaces in 100 mM phosphate-buffered saline. Data show that PS particles adhered ... More
Persistence of Streptococcus mutans in stationary-phase batch cultures and biofilms.
AuthorsRenye JA, Piggot PJ, Daneo-Moore L, Buttaro BA
JournalAppl Environ Microbiol
PubMed ID15466565
Streptococcus mutans is a member of oral plaque biofilms and is considered the major etiological agent of dental caries. We have characterized the survival of S. mutans strain UA159 in both batch cultures and biofilms. Bacteria grown in batch cultures in a chemically defined medium, FMC, containing an excess of ... More
RAGE-mediated neutrophil dysfunction is evoked by advanced glycation end products (AGEs).
AuthorsCollison KS, Parhar RS, Saleh SS, Meyer BF, Kwaasi AA, Hammami MM, Schmidt AM, Stern DM, Al-Mohanna FA
JournalJ Leukoc Biol
PubMed ID11867681
The accumulation of advanced glycation end products (AGEs) in the tissue and serum of subjects with diabetes has been linked to the pathogenesis of vascular complications. Because diabetes may be also complicated by increased susceptibility to recurrent infection, we investigated the effects of AGEs on human neutrophils, because their burst ... More
Biomass and porosity profiles in microbial granules used for aerobic wastewater treatment.
AuthorsTay JH, Tay ST, Ivanov V, Pan S, Jiang HL, Liu QS
JournalLett Appl Microbiol
PubMed ID12680942
AIMS: To obtain biomass and porosity profiles for aerobically grown granules of different diameters and to determine a suitable range of granule diameters for application in wastewater treatment. METHODS AND RESULTS: Microbial granules were cultivated in an aerobic granulated sludge reactor with model wastewaters containing acetate, or ethanol plus acetate, ... More
Microbiological aspects of an in situ model to study effects of antimicrobial agents on dental plaque ecology.
AuthorsGiertsen E, Guggenheim B, Thurnheer T, Gmür R
JournalEur J Oral Sci
PubMed ID11037756
This study validates an in situ model for ecological studies of dental plaque exposed to various antimicrobial agents with different modes of action on plaque bacteria. Eleven subjects wore two acrylic appliances, each containing two bovine enamel discs, during two 1-wk test periods. Using a split-mouth crossover design, the appliances ... More
Dielectrophoretic concentration and separation of live and dead bacteria in an array of insulators.
AuthorsLapizco-Encinas BH, Simmons BA, Cummings EB, Fintschenko Y
JournalAnal Chem
PubMed ID15018553
Insulator-based (electrodeless) dielectrophoresis (iDEP) is an innovative approach in which the nonuniform electric field needed to drive DEP is produced by insulators, avoiding problems associated with the use of electrodes. Live and dead Escherichia coli were concentrated and selectively released by applying stepped DC voltages across a microchannel containing an ... More
Broad-spectrum biofilm inhibition by a secreted bacterial polysaccharide.
AuthorsValle J, Da Re S, Henry N, Fontaine T, Balestrino D, Latour-Lambert P, Ghigo JM
JournalProc Natl Acad Sci U S A
PubMed ID16894146
The development of surface-attached biofilm bacterial communities is considered an important source of nosocomial infections. Recently, bacterial interference via signaling molecules and surface active compounds was shown to antagonize biofilm formation, suggesting that nonantibiotic molecules produced during competitive interactions between bacteria could be used for biofilm reduction. Hence, a better ... More
A nodule-specific dicarboxylate transporter from alder is a member of the peptide transporter family.
AuthorsJeong J, Suh S, Guan C, Tsay YF, Moran N, Oh CJ, An CS, Demchenko KN, Pawlowski K, Lee Y
JournalPlant Physiol
PubMed ID15001700
Alder (Alnus glutinosa) and more than 200 angiosperms that encompass 24 genera are collectively called actinorhizal plants. These plants form a symbiotic relationship with the nitrogen-fixing actinomycete Frankia strain HFPArI3. The plants provide the bacteria with carbon sources in exchange for fixed nitrogen, but this metabolite exchange in actinorhizal nodules ... More
Enumeration of water-borne bacteria using viability assays and flow cytometry: a comparison to culture-based techniques.
AuthorsHoefel D, Grooby WL, Monis PT, Andrews S, Saint CP
JournalJ Microbiol Methods
PubMed ID14607402
Maintaining optimal conditions in catchments or distribution systems relies heavily on water authorities having access to rapid and accurate water quality data, including an indication of bacteriological quality. In this study, the BacLight bacterial viability kit and carboxyfluorescein diacetate (CFDA) were coupled with flow cytometry (FCM) for rapid detection of ... More
Characterization of monospecies biofilm formation by Helicobacter pylori.
AuthorsCole SP, Harwood J, Lee R, She R, Guiney DG
JournalJ Bacteriol
PubMed ID15126474
As all bacteria studied to date, the gastric pathogen Helicobacter pylori has an alternate lifestyle as a biofilm. H. pylori forms biofilms on glass surfaces at the air-liquid interface in stationary or shaking batch cultures. By light microscopy, we have observed attachment of individual, spiral H. pylori to glass surfaces, ... More
Human NKT cells express granulysin and exhibit antimycobacterial activity.
AuthorsGansert JL, Kiessler V, Engele M, Wittke F, Röllinghoff M, Krensky AM, Porcelli SA, Modlin RL, Stenger S
JournalJ Immunol
PubMed ID12626573
Human NKT cells are a unique subset of T cells that express an invariant V alpha 24 TCR that recognizes the nonclassical Ag-presenting molecule CD1d. Activation of NKT cells is greatly augmented by the marine sponge-derived glycolipid alpha-galactosylceramide (alpha GalCer). Because human monocyte-derived cells express CD1d and can harbor the ... More
The YSIRK-G/S motif of staphylococcal protein A and its role in efficiency of signal peptide processing.
AuthorsBae T, Schneewind O
JournalJ Bacteriol
PubMed ID12700270
Many surface proteins of pathogenic gram-positive bacteria are linked to the cell wall envelope by a mechanism requiring a C-terminal sorting signal with an LPXTG motif. Surface proteins of Streptococcus pneumoniae harbor another motif, YSIRK-G/S, which is positioned within signal peptides. The signal peptides of some, but not all, of ... More
Identification of a protein secretory pathway for the secretion of heat-labile enterotoxin by an enterotoxigenic strain of Escherichia coli.
AuthorsTauschek M, Gorrell RJ, Strugnell RA, Robins-Browne RM
JournalProc Natl Acad Sci U S A
PubMed ID12011463
Enterotoxigenic Escherichia coli (ETEC) is an enteric pathogen that causes cholera-like diarrhea in humans and animals. ETEC secretes a heat-labile enterotoxin (LT), which resembles cholera toxin, but the actual mechanism of LT secretion is presently unknown. We have identified a previously unrecognized type II protein secretion pathway in the prototypic ... More
Protein expression by Streptococcus mutans during initial stage of biofilm formation.
AuthorsWelin J, Wilkins JC, Beighton D, Svensäter G
JournalAppl Environ Microbiol
PubMed ID15184181
Cells growing on surfaces in biofilms exhibit properties distinct from those of planktonic cells, such as increased resistance to biocides and antimicrobial agents. In spite of increased interest in biofilms, very little is known about alterations in cell physiology that occur upon attachment of cells to a surface. In this ... More